There is No New Planet
People need to grasp that humans will never colonize any other planet. We have exactly one chance, and Earth is it.
As our population on planet Earth exceeds 8 billion people, and as the planet continues to be abused by our species, it is becoming increasingly popular for people to discuss some fictional future where humans somehow transition to another planet, or even “terraform” another planet to make it livable for humans. We are, after all, the species who figured out how to walk on the moon, so why not? Well, it is complete fantasy, and will never happen. Let me tell you why.
Distances in Interstellar Space
Most people have difficulty imagining the distances involved when moving around the Universe. Landing humans on the Moon was a terrific accomplishment. But the Moon is only in our back yard — — on average just 238,900 miles from Earth. We know that there are no other habitable planets in our own solar system. Proxima Centauri is the closest star to our Sun at only 4.2 light years away. A light year is the distance that light travels in a vacuum in one year, equal to 5.88 trillion miles. So that means that Proxima Centauri is about 104 million times farther than the Moon. But Proxima is just next-door to us, and truthfully the solar system belonging to this red dwarf star looks like a terrible place to try to establish a colony, with tidally locked planets and bursts of life-killing radiation.
We move a little farther into space to reach the TOI-700 solar system. This system looks a little more promising, but now we are talking about 101 light years distant. This solar system is also orbiting an M class star, and although it looks better for life than Proxima, it is not optimal.
Let’s move on to another spiral arm of the Milky Way galaxy to find a suitable singlet G type star with Earth-sized rocky planets in the habitable zone. We haven’t found such a system yet, but we will. However, now we may be looking at distances of tens of thousands of light years.
Or perhaps we give up on finding a suitable home in the Milky Way galaxy. There are about 100 billion stars making up the Milky Way, but maybe we want to go to another galaxy to find our new home. Well the nearest spiral galaxy to the Milky Way is Andromeda. There are plenty of possible new homes in Andromeda, since there are approximately 1 trillion stars, and trillions of planets and moons comprising this galaxy. But now distances from Earth will be in the ballpark of 2.5 million light years.
It is estimated that there are maybe 2 trillion other galaxies in the Universe — — but now we might be talking about distances in the billions of light years.
Times for Traveling in Interstellar Space
The fastest humans have ever travelled is about 25,000 mph on the Apollo spacecraft. The fastest unmanned craft to date is the Parker Solar Probe that reached about 435,000 mph in solar orbit. This is very fast, but light travels at 186,000 miles every second, so the Parker Probe was only moving at about 0.00065 times light speed. So what does this mean?
To reach the Moon on Apollo or Artemis takes humans about 4–7 days. To reach Proxima at Apollo speed would take about 114,000 years — — a bit too slow. If we could perhaps go the speed of the Parker Probe, the time would shrink to about 6,500 years. Still a very long time (about the time since the first human civilization in Mesopotamia until the present). So what if we find some way to go really fast? Let’s think about a spaceship moving at 10% of light speed. Now Proxima is within reach at only 45 years away including time for acceleration and deceleration.
But 10% light speed is not fast enough for TOI-700 since this would still take over 1000 years one way. Andromeda would be 25 million years away at 10% light speed.
Will there ever be worm holes or warp speeds, quantum gravity or matter/anti-matter engines? I really doubt it. Not because some of the ideas may not be technically feasible, but I suspect the energy requirements will be completely impractical.
Resources Required to Travel in Interstellar Space
The MIT Technology Review reported that it would require a minimum of 98 carefully chosen settlers to embark on the 6,300 year multi-generational journey to the planet Proxima b. This number is required to prevent inbreeding and to account for various fatalities along the way. We are talking about a trip that will take 200 to 300 generations of humans which will never visit Earth or Proxima. The lack of gravity, the radiation, the chances of a collision with a meteor, the possibility of disease or mental illness, the chance of violence on board — — well, I don’t give this ship very good odds of reaching Proxima. If they reach Proxima b, they will be likely to find a planet that is uninhabitable.
Humans use a huge amount of energy each year. Including all oil, gas, coal, nuclear, solar, etc. humans produce and consume about 4 x 1020 Joules of power each year. So imagine accelerating a large spaceship to 10% light speed, traveling to a nearby star and decelerating the ship. I am thinking of something larger than the space shuttle, but smaller than the Starship Enterprise. Maybe something like a typical 180,000 ton Norwegian Cruise ship. In rough numbers, it would take about 400 years of production of all of the energy humans are currently producing to send this ship to a nearby star. Could we consider putting a large nuclear fission breeder reactor and a substantial portion of Earth’s accessible uranium on board? Maybe yes, but this would only be one starship, with a small group of colonists. In fact, anything that we start to consider relating to space uses an enormous amount of our resources. The concept of terraforming a planet like Mars (for example) would require far more resources than exist on planet Earth. Think about what humans have done on Earth for the last 100 years to only raise CO2 levels from 280 ppm to 400 ppm in our atmosphere. This gives you an idea of the scale required to make a change to a planet.
There is no New Planet. Learn to Use Earth Responsibly
Because of the enormous distances, the long travel times required and the impossible quantity of resources required, humans will never transition to a new planet, nor terraform a planet to make it livable for humans. It is fair to say that while we will continue to make great strides exploring the Universe using probes and telescopes, humans will not establish meaningful colonies on other planets. We may establish a working base on the Moon, and we may send a few people to visit Mars (hopefully Elon?) to demonstrate that we can. We will never be sending a million people to a planet in Andromeda. Having this fantasy, or worse, spending resources on it will only distract us from doing the incredibly difficult things that we must do on Earth.
Earth is unique and precious. As far as we know, it is one of a kind (probably not, but we don’t know yet). For humans to survive, we need to begin immediately working together to protect and preserve this beautiful blue and green planet. Think conservation, low consumption, recycling, re-use, re-purposing, no growth, reduce population, preserve nature, transition from fossil fuels and make everything in our lives sustainable. Is it possible for humanity to find a way to preserve civilization and knowledge in harmony with nature for the next 100 years, 500 years, 10,000 years, or 100,000 years? We have never faced such a challenge, but the time to start working on this transition is now (actually 100 years ago, but better late than never). All of the countries on Earth need to face this challenge and put short and long term strategies in place to save this planet from human folly. Only by living sustainably (at steady state in harmony with nature) can future generations of humans continue to live joyous lives on this lovely planet. Finding a planet Earth 2.0 is definitely not an option.
I encourage everyone to read the brilliant book by Thomas Murphy: Energy and Human Ambitions on a Finite Planet. This is available free on line at https://escholarship.org/uc/energy_ambitions or in hard copy at Lulu.com. Also, I recommend the classic book by Peter D. Ward and Donald Brownlee, Rare Earth: Why Complex Life is Uncommon in the Universe. This book is also available free on line or hard copies from Amazon.
